Is my iPhone beyond repair?

Hi, so I broke my iPhone SE (1st gen) screen and went to repair the screen myself (have done this before on this phone) but the screen remained black despite the phone being on (e.g. when I plugged in the charger I can hear the *ding*.)

I tried the screen on my spare iPhone 5 and the screen works fine so it is not faulty. I have tried many variations of resetting the phone… holding down power/+home button and no luck so far. Is it likely I have damaged the motherboard and therefore it’s beyond repair?

I’m aware I cannot backup the SE on my laptop as it requires unlocking. Could I switch the motherboard over from my iPhone 5 to try and get it working at least to backup?

Have given up and bought a new SE either way, but curious whether there are any more things I can try before I dispose of it :(